New Synchronizer workflow

 - synchronizer will synchronize only those extSource members with
   correct informations and attributes
 - method getCandidate from extSource and login will change firstName
   and lastName on null if in not correct format
 - methods createMember* will throw WrongAttributeValueException and
   WrongReferenceAttributeValueException instead of consistency
   exception, because this is not the same
 - new ParserException created for parser errors in Perun
 - method synchronizeGroup will return String with info about skipped
   members and the reason why were skipped
 - method synchronizeGroups will set exception to attribute for this
   purpose to inform user about skipped extSource's members
 - when some problem occurs (like parserException,
   attributeValueException, candidateNotExistsException) in
   synchronization, member of extSource which create this exception will
   be skipped and information about this skipping will be add to
   attribute with info about last synchronization of group